Re: [RFC PATCH 0/4] pinctrl: rockchip: PREEMPT_RT_FULL fixes

Heiko Stuebner
2017-03-15T17:09:52Z

Am Montag, 13. März 2017, 18:38:09 CET schrieb John Keeping:
> As described in Documentation/gpio/driver.txt, we should not be using
> sleepable APIs in the irqchip implementation. Since this includes the
> regmap API, this patch series ends up moving the mux setup for IRQs into
> an irq_bus_sync_unlock() handler which may result in the IRQ being
> configured before the port has been muxed as a GPIO.
>
> I've marked the series as RFC because I'm not sure if this is the best
> way to accomplish this or if there is another approach that is cleaner.
> Also, the first patch may not be correct on RK3399 because I originally
> wrote the patch for RK3288 on top of v4.4 where all drive updates only
> affect a single register. We don't need locking in this case because
> regmap_update_bits() takes a lock on the regmap internally, but if these
> two registers need to be updated atomically then another lock will
> be required here - slock cannot be used if it is converted to a raw
> spinlock since with full RT preemption the regmap's spinlock may sleep.

With the issue in patch2 fixed and top of the current head of Linus T's tree
(4.11-rc2 + some patches), at least rk3036, rk3288, rk3368 and rk3399 come up
nicely including multiple (1 to 3 per board) gpio-interrupts, so this series

Tested-by: Heiko Stuebner <heiko@sntech.de>